I visited the Emerson Point Preserve in Palmetto, Florida in April 2014, a peninsula on the border of the Manatee River and Tampa Bay. On the map it is on an island, but this is only because of a small canal. The preserve rules prohibit collecting, walking off-trail, and alcohol. Despite this, it was still pretty fun.
Maybe these trees are old and have been subject to a lot of weathering including tropical storms that reshaped their branches. They are definitely unusual and worth a visit to the Preserve. (I assume they are mangrove trees.)